Handrails, whether above horizontal surfaces, slopes or stairs, are generally supported on a series of posts whose lower ends are fastened to the underlying base surface via some form of stanchion. As the structural “backbone” of a handrail system, the stanchion is required to withstand high levels of stress whenever the handrail is impacted by strong external force. For child protection and public safety, building code regulations call for some form of safety grillwork or mesh extending across the space between the posts, typically extending down to a bottom safety member. Safety, building and code regulations limit the separation between safety members, and also limit the spacing between the bottom safety member and the underlying base surface, thus raising physical interference issues since installation of the bottom safety member requires it to pass through the posts in the same low end region already necessarily occupied by the stanchions.
Many different design approaches have been created to balance the conflicting demands of facilitating installation and meeting code requirements while also enabling freedom in ornamental and architectural design. Virtually all known handrail systems have as a common basis a bottom safety member which is often implemented as a wire, rod, twisted or braided cable or equivalent, usually of metal, e.g. stainless steel, or alternatively, suitably strong plastics, fiberglass/epoxy, carbon fibre and the like. Commonly the bottom safety member is procured in continuous length and passed through each post; typically requiring drilling through the posts as required at installation.
If the post is hollow and based on a stanchion, the standing portion of the stanchion must extend far enough up into the lower end of the post to ensure required overall handrail structural strength, especially to withstand strong lateral forces impacting the handrail region, which by leverage, translate to extremely high compressive and bending stresses on the stanchions at the low end of the posts. In practice, the stanchion height is typically made to extend above the upper limit for height of the bottom safety member allowed by code, while the height selected for ornamental design purposes can range far below the code limit, consequently installation of handrail systems using stanchions of known art routinely requires drilling not only through the hollow post walls but also through the (usually solid steel) stanchion, a burden that makes installation very tedious, time-consuming and costly.